Flocculation of wine yeasts: frequency, differences, and stability of the character

Abstract

Flocculating ability in yeasts of the genus Saccharomyces which cause the spontaneous fermentation of grape musts is not rare; .apprx. 6.8% of isolates are flocculent. The strains show a different degree of flocculation and variable developmental behavior. Genetic analysis, carried out immediately after strain isolation and again after 3 yr, shows that only flocculating homozygote strains ensure the stability of the flocculation character over time. Flocculation of some strains shows a degree of instability in the expression of the character which is typical of cytoplasmic inheritance.